1. Field of the Invention
The invention relates to an audio reproduction apparatus, more particularly to an audio reproduction apparatus that can ensure a stable audio signal transmission, and that can provide a wide audio reproduction area, and that has a relatively low cost.
2. Description of the Related Art
FIG. 1 illustrates a conventional audio reproduction apparatus that includes an audio amplifier 111 having an output side 110 for outputting audio signals and an output voltage, and an impedance matching network 13 coupled electrically across the input side 110. The audio amplifier 11 includes an amplifier 111, and a transformer 112 coupled electrically to the amplifier 111 for increasing the output voltage from the audio amplifier 11. The impedance matching network 13 includes a plurality of loudspeakers 131 that are coupled electrically in series or parallel to each other.
The following are some of the drawbacks of the conventional audio reproduction apparatus:
1. For optimum power transmission, an output impedance across the output side 110 should be equal to a total impedance of the impedance matching network 13, thereby resulting in a complex impedance design for the impedance matching network 13. Furthermore, since the impedance matching network 13 has so many impedance components, attenuation of frequency response of audio frequency occurs, thereby resulting in poor audio reproduction quality.
2. When the number of the loudspeakers 131 in the impedance matching network 13 is increased, the output impedance may not match the total impedance of the impedance matching network 13, thereby resulting in a limited number of the loudspeakers 131 that can be incorporated in the impedance matching network 13.
3. When it is necessary to increase the number of the loudspeakers 131 in the impedance matching network 13, another audio amplifier, which can provide higher output power, must be installed to replace the audio amplifier 11, thereby resulting in higher costs.
Therefore, the object of the present invention is to provide an audio reproduction apparatus that can overcome the drawbacks associated with the aforesaid prior art.
According to the present invention, an audio reproduction apparatus comprises:
a primary audio amplifier having an output side for outputting audio signals; and
a plurality of auxiliary audio amplifiers coupled electrically in series to the primary audio amplifier, each of the auxiliary audio amplifiers having an input side for receiving the audio signals from the primary audio amplifier, a signal current generating device coupled electrically across the input side such that the audio signals pass through the signal current generating device, a current inducing device disposed adjacent to the signal current generating device for generating induced audio signals when the audio signals pass through the signal current generating device, an auxiliary amplifier coupled electrically to the current inducing device for amplifying and outputting the induced audio signals generated thereby, and a loudspeaker coupled electrically to the auxiliary amplifier for reproducing the induced audio signals amplified by the auxiliary amplifier.